Scharlau Ingrid
Department of Psychology, Bielefeld University, PO Box 10-01-31, D-33501 Bielefeld, Germany.
Q J Exp Psychol A. 2004 Nov;57(8):1411-36. doi: 10.1080/02724980343000828.
The spatial distribution of visual attention is a yet unresolved question. One of the main topics is whether attention is distributed in a graded fashion around an attended location (e.g., Downing, 1988; Zimba & Hughes, 1987). The present experiments explore whether, and on which conditions, gradients of attention arise and contribute to perceptual facilitation. A masked or unmasked prime precedes one of two targets whose temporal order has to be judged. The prime captures attention, which shortens the perceptual latency of the primed target (perceptual latency priming; Scharlau & Neumann, 2003a; Shore, Spence, & Klein, 2001). No strong evidence for an attentional gradient was found. (1) Accuracy of temporal order judgements was independent of the distance between the two targets that were judged. That is, facilitation of the second target by the first target was spatially invariant. (2) With targets of short duration, facilitation was independent of prime-target distance. (3) With targets of long duration, gradients were found: Facilitation declined continuously with distance. Thus, long duration of stimuli may be a sufficient precondition for an attentional gradient. A control experiment showed that object-based attention contributes only marginally to perceptual latency priming.
视觉注意力的空间分布仍是一个未解决的问题。主要议题之一是注意力是否围绕被关注位置以渐变方式分布（例如，唐宁，1988；津巴和休斯，1987）。本实验探究注意力梯度是否以及在何种条件下会出现并有助于知觉促进。在必须判断时间顺序的两个目标之一之前呈现一个掩蔽或未掩蔽的启动刺激。启动刺激会吸引注意力，从而缩短被启动目标的知觉潜伏期（知觉潜伏期启动；沙劳和诺伊曼，2003a；肖尔、斯彭斯和克莱因，2001）。未发现注意力梯度的有力证据。（1）时间顺序判断的准确性与被判断的两个目标之间的距离无关。也就是说，第一个目标对第二个目标的促进在空间上是不变的。（2）对于持续时间短的目标，促进作用与启动刺激 - 目标的距离无关。（3）对于持续时间长的目标，发现了梯度：促进作用随距离持续下降。因此，刺激的长时间持续可能是注意力梯度的一个充分前提条件。一项对照实验表明，基于对象的注意力对知觉潜伏期启动的贡献很小。
